Active and adaptive tire systems

ABSTRACT

An active and adaptive tire system is disclosed. The active and adaptive tire system comprises a tire and an active material configured to alter at least one characteristic of the tire in response to at least one condition. Also disclosed are an intelligent tire system and a method of monitoring a condition.

RELATED APPLICATION

This application is a division of application Ser. No. 12/049,416 filedMar. 17, 2008, which is hereby fully incorporated herein by reference.

FIELD OF THE INVENTION

The invention generally relates to intelligent tire systems. Moreparticularly, the invention relates to active tire systems capable ofsensing conditions and characteristics and dynamically adapting thereto.

BACKGROUND OF THE INVENTION

Tire pressure monitoring systems (TPMS) are used to monitor conditionswithin and surrounding vehicle tires. Parameters typically monitoredinclude local temperature and pressure information. Many TPMS comprisetire-based sensors and other components that monitor and then transmitthe local information via radio signals to a central receiver in anotherpart of the vehicle. Power is supplied to the tire-based systems bylocal batteries, energy harvesters or scavengers, or other means.

Traditional TPMS are passive: the systems monitor one or more vehicletires and optionally the ambient environment but do not interact with orprovide feedback to the tires to actively adjust or compensate forsensed conditions. A driver may therefore be automatically notified of acondition, but any necessary or desired adjustment must be manuallyaccomplished. For example, if snow or ice or hazardous drivingconditions are detected, a driver may alter his or her driving behavior,such as by slowing down and judiciously applying the brakes, or bychanging to winter or snow tires at the next opportunity. Problems maystill result, however, if a driver makes insufficient or incorrectdriving behavior alterations. Further, frequent changing of tires toconform to various driving and road conditions is impractical andexpensive.

SUMMARY OF THE INVENTION

One embodiment of the invention is an active and adaptive tire system.The active and adaptive tire system comprises a tire and an activematerial configured to alter at least one characteristic of the tire inresponse to at least one condition.

Another embodiment of the invention is an intelligent tire system. Theintelligent tire system comprises at least one tire comprising amaterial having a response to a trigger, a wheel module proximate thetire and comprising a sensor configured to sense a condition andcircuitry configured to selectively trigger the material based on thecondition, and a control 10 unit communicatively coupled to the wheelmodule.

In a further embodiment, the invention is a method of monitoring acondition. A tire is formed including an active material having aresponse to a condition. A condition is sensed, triggering the response,and at least one characteristic of the tire is altered by the response.

The above summary of the invention is not intended to describe eachillustrated embodiment or every implementation of the present invention.The figures and the detailed description that follow more particularlyexemplify these embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention may be more completely understood from the followingdetailed description of various embodiments in connection with theaccompanying drawings, in which:

FIG. 1 is a block diagram of a vehicle in accordance with an embodimentof the invention.

FIG. 2 is a cross-sectional view of a wheel in accordance with anembodiment of the invention.

FIG. 3A is a cross-sectional view of a wheel in accordance with anembodiment of the invention.

FIG. 3B is another cross-sectional view of the wheel of FIG. 3A.

FIG. 4A is a cross-sectional view of a wheel in accordance with anembodiment of the invention.

FIG. 4B is another cross-sectional view of the wheel of FIG. 4A.

FIG. 5 is a cross-sectional view of a wheel in accordance with anembodiment of the invention.

FIG. 6 is a block diagram of a wheel module in accordance with anembodiment of the invention.

While the invention is amenable to various modifications and alternativeforms, specifics thereof have been shown by way of example in thedrawings and will be described in detail. It should be understood,however, that the intention is not to limit the invention to theparticular embodiments described. On the contrary, the intention is tocover all modifications, equivalents, and alternatives falling withinthe spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE DRAWINGS

The invention is related to next-generation intelligent tire systems,such as active and adaptive tire systems and methods. Variousembodiments of the invention can sense actual tire, road and drivingconditions and characteristics, and/or respond to externally controlledinfluences, and dynamically adapt thereto, thereby improving vehicle andpassenger safety. The invention can be more readily understood byreference to FIGS. 1-6 and the following description. While theinvention is not necessarily limited to the specifically depictedapplication(s), the invention will be better appreciated using adiscussion of exemplary embodiments in specific contexts.

Referring to FIG. 1, an intelligent tire system (ITS) 100 according toan embodiment of the invention is depicted. ITS 100 is implemented in avehicle 102, which can comprise an automobile, SUV, truck, semi-truck,bus, motorcycle, or other vehicle having two, four, or some other numberof wheels and tires. As depicted and described in the example thatfollows, vehicle 102 has four wheels 104 and is but one example of asuitable vehicle for implementing various embodiments of ITS 100.

Referring to FIG. 2, each wheel 104 typically comprises a tire 106including an inner liner 108 that lines the inside of tire 106, multipleply layers (not shown) over the inner liner, and one or more steel beltsover the ply layers (not shown). A cushion layer and a base layer (notshown) are situated over the steel belts and a cap layer 110, alsoreferred to as the tread layer, is situated on the outside of tire 106over the base layer. A tread portion 112 interacts 10 with the roadsurface to provide traction. The entire tire structure 106 is thenmounted on a rim 114, forming wheel 104, and coupled to an axle ofvehicle 102.

In various embodiments of the invention, one or more tires of vehicle102 further comprise additional material layers or portions of embeddedmaterial that are active and can adapt to changing driving surface,tire, wheel, vehicle and/or other external conditions. This 15adaptation can comprise, in one embodiment, a change in one or moremechanical properties of the tire, such as surface hardness,flexibility, rigidity, roughness or profile. In further embodiments,adaptations can comprise increasing or decreasing tire pressure and/oraltering friction effects related to driving surface or speed by raisingor lowering a tire temperature. These and other adaptations can beelectrically and/or mechanically induced or can be 20 effected by anexternal electric or magnetic field or other force in variousembodiments.

In FIG. 3A, tire 106 further comprises an active portion. In oneembodiment, the active portion comprises an active material layer 116applied on or over at least a portion of cap layer 110. For example,active portion 116 can be laminated or adhered to cap layer 110. Inanother embodiment, active material layer 116 is integrally formed withat least a portion of an outer surface of cap layer 110. In a furtherembodiment, active material layer is embedded within tire 106, forexample in or to cap layer 110, between cap layer 110 and inner liner108, between cap layer 110 and a thin protective outer layer, and oramong other layers of tire 106, such as those described above. In yetanother embodiment, active material layer 116 comprises a plurality ofindividual layers arranged adjacent to or apart from one another on orwithin tire 106. As depicted in FIG. 3A, active material layer 116corresponds 5 to substantially the entire external surface of tire 106.In other embodiments, active material layer 116 is limited to some orall of tread portion 112, to tread portion 112 as well as at least aportion of the sidewall of tire 106, or to some other configuration.

In the embodiment of FIG. 4A, the active portion comprises at least oneactive material element 118. Active material elements 118 can comprisestrips, beads, sections, or 10 other configurations and can be appliedto or embedded partially or wholly within cap layer 110 in tread area112. In one embodiment, active material elements 118 form at least partof the tread of tire 106. In another embodiment, one or more activematerial elements are also located in a sidewall or other portion oftire 106. In embodiments comprising a plurality of active materialelements 118, whether arranged in tread area 112 or a sidewall portionor both, 15 adjacent elements 118 can be spaced in a regular orirregular manner.

In FIG. 5, tire 106 includes an active portion comprising embeddedparticles 120. In one embodiment, particles 120 are embedded in treadarea 112 of cap layer 110. In other embodiments, particles 120 areembedded in additional or other layers of tire 106, in additional orother areas of tire 106, or in further beneficial configurations. In oneembodiment, embedded particles 120 are integrally formed with thematerial(s) of tire 106 during manufacture. In other embodiments,particles 120 are embedded via injection or some other suitable process.

Various combinations of the embodiments depicted in FIGS. 3A, 4A and 5and described above can be used in other embodiments of the invention.For example, particles 120 can be embedded within cap layer 110 andactive material elements 118 applied to an external surface of cap layer110. Other combinations of active material layer 116, active materialelements 118, particles 120 and additional active materialconfigurations can also be used.

The active portion or portions of tire 106, such as active materiallayer 116, active material elements 118, and particles 120, can compriseone or more variable materials. For example, an active piezoelectricmaterial is used in one embodiment. The piezoelectric material cancomprise a layer, film, foil, particle, strand, strip, or otherconfiguration or combination thereof in various embodiments of theinvention. Piezoelectric materials respond to triggers, such as externalelectric fields, a change in a charge state of internal electricdipoles, a change in temperature, and or a change in a variableresistance electric load, by 10 altering a characteristic or property,such as length. A change in a characteristic or property of thepiezoelectric material can also effect a change in tire 106 in which thematerial is embedded, applied, or otherwise located. The piezoelectricmaterial can be applied to, formed on or with, or otherwise supported bya base portion or layer, such as polypropylene, thermoplasticfluorpropylene, fluorinated ethylene, propylen-copolymere,polyvinylidene, and other suitable materials, although in someembodiments a base layer is omitted.

In other embodiments, the active portion or portions of tire 106comprise a magnetostrictive material or a combination of piezoelectricand magnetostrictive materials. Various properties of magnetostrictivematerials can be manipulated or influenced by external magnetic fields,temperature changes, andor variable resistance electrical loads. Forexample, an external magnetic field can induce a change in dimension ofa magnetostrictive layer or portion in tire 106, thereby altering one ormore properties, characteristics, or behaviors of tire 106. Basematerials in embodiments comprising magnetostrictive materials caninclude, for example, flexible magnetic alloys such as FeSiB, FeCo, FeSior FeSiB. Such materials can be manipulated by external magnetic fieldsto alter one or more dimensions or characteristics of tire 106, therebyproviding a beneficial driving and or vehicle handling effect.

Permanent magnetic materials can also be used in other embodiments.Examples of suitable materials include or can comprise FeNdB, CoSm,AlNiCo, and FeTb, among others. The anisotropy of such permanentmagnetic materials can be exploited by the proper orientation ofmagnetic fields.

In further embodiments, such as those depicted in FIGS. 4A-5, the activeportion or portions of tire 106 can comprise foam, microplasma, and/orsimilar materials having electric dipoles that are variable or capableof being manipulated to provide a beneficial effect. These materials canbe embedded within, injected into, or othenvise formed with one or morelayers or portions of tire 106 to form composite material layers orportions. For example, foam or microplasma materials can be injectedinto cap layer 110 in one embodiment.

Additional materials can also be suitable in other embodiments. Forexample, polymers or other materials having a susceptibility tomoisture, humidity, or a similar condition can be used. In oneembodiment, a material having moisture diffusion permeability alters oneor more characteristics, such as by swelling or expanding, in responseto a change in humidity.

Simple metallic and/or magnetic particles, such as in the embodiments ofFIGS. 4A and 5, can also be used. Such particles could be influenced byexternal changes in temperature. In one embodiment, these changes intemperature can be effected by irradiation of an alternatingelectromagnetic field. This irradiation can lead to heat dissipation bychanges in magnetization and eddy current losses. By localizing theparticles, for example as depicted in FIG. 4A and/or in inner layers oftire 106, changes can be effected in only certain desired areas of tire106.

In accordance with the various embodiments described above, increaseddriving safety and security through better adherence of tire 106 on theroad surface can be provided when a change in a characteristic of tire106 is effected by the aforementioned active portion or portions of tire106, such as active material layer 116, active material elements 118,and particles 120. In particular, the active portions can provide areal-time adjustment to currently prevailing driving, road, and/or tireconditions. In one embodiment, a profile or surface characteristic oftire 106 can be altered to better respond to, for example, icy, snowy,or rainy driving conditions. In another embodiment, a different physicalcharacteristic, such as a hardness of one or more material layers oftire 106, is altered to provide better friction or adherence to aparticular driving surface.

Comparing FIGS. 3A and 3B, a change in active material layer 116 and caplayer 110 can be seen. Such a change can, for example, increase ordecrease a tread depth, increase or decrease the contact area (or“footprint”) of tire 106 in tread area 112, or make some other oradditional change to provide a benefit to vehicle handling and safety.Similarly, in FIGS. 4A and 4B, a change in active material elements 118can provide increased or decreased adherence of tire 106 to a drivingsurface in response to, for example, icy driving conditions or a gravelroad surface.

These alterations can be automatic, such as in the case of activeportions responsive to moisture, humidity, and other conditions, orexternally influenced, such as in the case of magnetostrictive materialsresponsive to external magnetic fields. For either automatic orexternally influenced changes, but particularly in the embodiments ofthe latter, each wheel 104 can comprise a wheel module 124 of ameasurement and monitoring system (referring again to FIG. 1 in additionto FIG. 6). In other embodiments, fewer than all wheels 104 comprisewheel modules 124.

Each wheel module 124 is in communication with a central control unit126 via a communication module 128 located in each wheel module 124 andcentral control unit 126. Communication module 128 can comprise wiredand/or wireless circuitry in various embodiments. In the embodimentdepicted, central control unit 126 is mounted in vehicle 102. In otherembodiments, central control unit 126 can be external to vehicle 102.Central control unit 126 can be operable to monitor and control changesin each individual tire 106 such that overall driving safety andstability are not compromised because of sudden or disparate changes inone or more tires 106. For example, if vehicle 102 suddenly swerves andthe two right-side wheels 104 leave a paved driving surface andencounter a gravel shoulder, a sudden adjustment by any of the tires 106to compensate for the different driving surfaces could further endangerstability of vehicle 102 and hamper a driver's ability to regaincontrol. In such situations, central control unit 126 can temporarilyinhibit automatic or effected changes in all wheels 104 of vehicle 102.In other embodiments, central control unit 126 can calculate changes toone or more tires 106 that would assist a driver in regaining control.In further embodiments, central control unit 126 is also incommunication with other vehicle safety systems, such as airbag,antilock braking, tire pressure, and the like, and can coordinate allsystems to maximize vehicle and occupant safety.

Each wheel module 124 comprises at least one sensor 130 adapted tomonitor the environment and conditions of and around wheels 104 in oneembodiment. Sensor 130 can comprise capacitive, pressure, temperature,moisture, magnetic, gas, photo, acoustic and/or other sensors in variousembodiments. In another embodiment, wheel module 124 comprises a sensoror sensor network coupled to or embedded within tire 106 of wheel 104.

In embodiments comprising materials influenced or controlled by externalforces, wheel module 124 comprises an external influence module 132. Inembodiments comprising, for example, magnetostrictive material, externalinfluence module 132 can comprise one or 20 more magnets to produce amagnetic field. In other embodiments, external influence module 132 cancomprise one or more devices operable to alter a temperature in oraround tire 106, as many of the aforementioned active materials can beinfluenced by changes in temperature. For example, external influencemodule 132 can comprise infrared emitters, microwave irradiators, and/orother external heat sources. In other embodiments, the one or more 25magnets are physically separate from but communicatively coupled towheel module 124 in order to effect field changes to influence theactive portion or portions of tire 106.

Wheel module 124 can further comprise one or more individual unitsdistributed within or about each wheel 104. For example, wheel module124 can comprise a first unit mounted in wheel 104, such as on the rimor to the inner liner, and a second unit mounted in a wheel wellproximate wheel 104 in one embodiment. In another example, eachcomponent of wheel module 124 (communication module 128, sensor(s) 130and magnet(s) 132) can be mounted separately in or around wheel 104. Invarious other embodiments, wheel module 124 comprises additionalcircuitry and components, such as circuitry to communication with theactive portion or portions of tire 106.

In use, the various embodiments of the invention depicted and describedherein can 10 improve vehicle and passenger safety by sensing andadapting to actual tire, road and driving conditions andcharacteristics. Further embodiments can respond to controlledinfluences, such as magnetic fields and heat sources, and dynamicallyadapt thereto, thereby improving vehicle and passenger safety.

Although specific embodiments have been illustrated and described hereinfor purposes of description of an example embodiment, it will beappreciated by those of ordinary skill in the art that a wide variety ofalternate and/or equivalent implementations calculated to achieve thesame purposes may be substituted for the specific embodiments shown anddescribed without departing from the scope of the present invention.Those skilled in the art will readily appreciate that the invention maybe implemented in a very wide variety of embodiments. This applicationis intended to cover any adaptations or variations of the variousembodiments discussed herein, including the disclosure information inthe attached appendices. Therefore, it is manifestly intended that thisinvention be limited only by the claims and the equivalents thereof.

1. An active and adaptive tire system comprising: a tire; and an activematerial configured to alter at least one characteristic of the tire inresponse to at least one condition.
 2. The system of claim 1, whereinthe active material is embedded within the tire.
 3. The system of claim2, wherein the active material comprises a plurality of particles. 4.The system of claim 2, wherein the active material comprises a layer. 5.The system of claim 1, wherein the active material comprises a layerapplied to an external surface of the tire.
 6. The system of claim 1,wherein the active material is configured to automatically alter the atleast one characteristic of the tire.
 7. The system of claim 1, furthercomprising a sensor, wherein the sensor is configured to sense the atleast one condition and the active material is configured to alter theat least one characteristic of the tire in response to the at least onecondition sensed by the sensor.
 8. The system of claim 1, wherein theactive material is selected from the group consisting of: apiezoelectric material, a magnetostrictive material, a combination of apiezoelectric material and a magnetostrictive material, a permanentmagnetic material, a foam, a microplasma, and a polymer.
 9. The systemof claim 1, wherein the at least one characteristic of the tire isselected from the group consisting of: a dimension, a tread depth, atread width, a footprint size, and a hardness.
 10. The system of claim1, wherein the at least one condition is selected from the groupconsisting of: a magnetic field, an electric field, an electromagneticfield, a driving surface condition, a moisture level, and a temperature.11. A method of monitoring a condition comprising: forming a tireincluding an active material having a response to a condition; sensingthe condition and triggering the response; and altering at least onecharacteristic of the tire by the response.
 12. The method of claim 11,further comprising mounting the tire on a vehicle.
 13. The method ofclaim 11, wherein forming a tire further comprises forming a layer ofthe active material in the tire.
 14. The method of claim 11, whereinforming a tire further comprises injecting the active material into atleast a portion of the tire.